How can I reorder the sequence of days in the date picker?

How can I reorder the sequence of days in the date picker? I mean in different countries the weak begins with differents days, for example in our country weak starts from monday. So different locales use different first days of weak. But in class DatePicker I can not redefine DateTimeFormatInfo:

setStartDay() mrthod doesn't work, because getCalculatedStartDay() is called in the constructor and it is impossible to redefine startDay field... One way to resolve this problem is to wright my own DatePicker. Is it right?